Messages in this thread | | | Date | Fri, 27 Mar 2020 13:09:34 -0700 | From | Tony Jones <> | Subject | Re: [PATCH] perf tools: update docs regarding kernel/user space unwinding |
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On Thu, Mar 26, 2020 at 04:32:26PM -0500, Paul Clarke wrote: > > + and 'lbr'. The value 'dwarf' is effective only if libunwind > > + (or a recent version of libdw) is present on the system; > > + the value 'lbr' only works for certain cpus. The method for > > + kernel space is controlled not by this option but by the > > + kernel config (CONFIG_UNWINDER_*). > > Your changes are just copying the old text, so this isn't a criticism of your patches. > > Do we have information to replace "a recent version of libdw", which will quickly get stale?
Hi Paul.
The original "(libunwind or a recent version of libdw)" text was from Feb 2016. So a while ago.
bd0419e2a5a9f requires >= 0.157 but this is for probing. 0a4f2b6a3ba50 specifies >= 0.158 but I see no mention of why in the commit but since it's from 2014 and elfutils is now at 0.178, I think it's safe to just remove the reference.
As an aside, there is a lot of detail in perf-config.txt that's available in some of the other subcomands help files. Seems a good way for things to get stale. It could also do with some grammatical cleanup.
Tony
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